1. Field of the Invention
The present invention relates to an apparatus and method for sequentially recording images on a front and back surfaces of a recording medium.
2. Description of the Related Art
A double-side image recording apparatus is commonly known, which records images on both the front and back surfaces of a recording medium. The double-side image recording apparatus has one image recording section and a conveying mechanism that can turn a recording medium upside down. The apparatus records an image on the front surface (first surface) of recording medium and then conveys the recording medium to a reversing path. The recording medium is turned upside down and re-supplied to the image recording section. The apparatus then records an image on the back surface (second surface).
Such a double-side image recording apparatus has one image recording section that records images of the first and second surfaces of a recording medium. Accordingly, if the timings for conveying the recording medium in recording an image on the first surface and in recording an image on the second surface through re-supply are not optimally controlled, the succeeding recording medium may collide with the recording medium on a conveying path for recording media.
A possible method for preventing such a collision involves finishing recording images on the first and second surface of a recording medium before the next succeeding recording medium is supplied. Another possible method involves providing a large inter-media distance (page gap) between two successive recording media in order to prevent collision. However, these methods may reduce the number of recording that the image recording apparatus can record per unit time. This may reduce throughput to degrade the value of the image recording apparatus.
Japanese Patent No. 3084763, for example, discloses a method for determining the conveyance start timing for the succeeding recording medium in performing consecutive double-side recording. This method involves setting the number of recorded sheets in terms of pseudo pages, on the basis of the length of the sheet conveying path and sheet length and then scheduling the conveyance start timing for the succeeding recording medium. Similarly, Japanese Patent No. 3178851 discloses a method of determining conveyance start timing for recording a recording medium by calculating the number of sheets that can be left in the conveying path.
Moreover, Japanese Patent No. 3068595 discloses a method, in which the number of insertions equal to the maximum number of sheets to be recorded on the first surface is calculated from the length of the sheet conveying path and the sheet length and the conveyance start timing for the recording medium is controlled on the basis of the calculation.
Japanese Patents Nos. 3084763, 3178851, and 3068595 predetermine the conveyance start timing for a recording medium from the length of the sheet conveying path and the sheet length. Thus, the image recording apparatuses may fail to schedule the conveyance start timing for the recording medium in real time, depending on when job information on image recording (image data, double-side/single-side recording instruction, recording medium media size instruction, recorded sheet number instruction, and the like) is received from a superordinate apparatus.
Further, if single-side recording and double-side recording are consecutively performed, the methods disclosed in the prior art cannot schedule the optimum conveyance start timing for each recording medium.